Sam McKay said the victims were a single mother and four of her children — aged six, seven, nine and 12.

“Most everybody is in shock right now,” he said. “It’s devastating for everybody.”

The woman had another older daughter who was away when the blaze broke out, McKay said, adding that three of her children were adopted.

Investigators had not yet arrived at the scene by Thursday afternoon, McKay said, so there was no word on what caused the fire.

He said everyone in the community of about 1,000 people is affected by the loss.

Grand Chief Alvin Fiddler of Nishnawbe Aski Nation said a team of crisis and support workers will be sent to the community, which is also known as Big Trout Lake.

“We were saddened to learn of the tragedy this morning and our prayers are with the victims, their families and the entire community during this difficult time,” Fiddler said in a statement. ”This is a devastating loss for the community.”